Two major sets of studies continue investigations into the pathology of the major functional psychoses. (a) Studies of smooth pursuit eye movement disorders have already been established as associated with psychosis (although it occurs in other conditions such as central nervous system and toxic disorders), and as having a genetic component. We now will try to clarify the central nervous system localization of pursuit disorders in psychosis and to explore the etiological significance of pursuit dysfunctions in studies of families with a high density for schizophrenia and in the Danish adoption sample. We will also develop and refine measures of saccadic reaction time. (b) We will continue studies of thought disorder using our Thought Disorder Index (TDI) for the purpose of discriminating types of thought disorder that are presumed to be associated with different functional psychoses and for detecting thought disorder in children with major psychopathology. We will also test the Danish adoption sample and high density families for the presence of thought disorder.